Mobile and stationary bulk liquid containers or tanks come in many different sizes and shapes, and are used both above ground and below ground. These tanks typically require openings or porting to allow liquid to be introduced and removed from the tank, for venting of the tank, and for inspection of the tank interior. In some applications, government regulations require capture and containment of any spillage to avoid environmental issues. Also, contamination ingress is a concern in some applications. The various tank openings are separate and independent from one another. Each opening requires a lid or cap which can be removed as needed. The largest opening is a manway to accommodate scheduled, mandatory inspections and recertification of the tank. The fill ports are usually located in the top of a tank. A discharge port may also be located in the top of the tank for removal of fluid by suction or pumping. A vent port is also located in the top of the tank to displace air when liquid is added to the tank. Each port in these prior art tanks requires a seal to preclude leakage into or from the tank, with each seal providing an opportunity for leakage failure.
Therefore, a primary objective of the present invention is the provision of an improved closure for bulk liquid containment tanks.
Another objective of the present invention is the provision a closure for a liquid containment tank manway opening with multiple ports formed in the closure to accommodate liquid filling and discharge from the tank.
Yet another objective of the present invention is the provision a multi-functional closure for a liquid containment tank which minimizes the risk of liquid leakage into or out of the tank.
Still another objective of the present invention is the provision of a closure for a liquid containment tank manway opening having an anti-spill reservoir to capture spilled liquids being introduced to or removed from the tank.
Another objective of the present invention is the provision of a closure for a liquid containment tank which incorporates all the necessary ports required by the tank.
Yet another objective of the present invention is the provision of a closure for a liquid containment tank opening which can be used on a flat-walled or curved-walled tank.
A further objective of the present invention is the provision of a tank closure which can be used on mobile and stationary liquid containment tanks.
Another objective of the present invention is a closure for use on flat and curved wall liquid containment tanks.
Still another objective of the present invention is the provision of a closure for a liquid containment tank opening which protects and secures multiple openings in the closure and into the tank.
A further objective of the present invention is the provision of a closure for a bulk liquid containment tank inspection opening which is easy and economical to manufacture, and safe and durable in use in filling, emptying, and inspecting the tank.
These and other objectives will become apparent from the following description of the invention.